1. Field of the Invention
The present invention relates generally to an intake pressure sensor arrangement for an engine, and more particularly to an improved intake pressure sensor arrangement for a multi-cylinder engine.
2. Description of Related Art
In all fields of engine design, there is increasing emphasis on obtaining high performance in output and more effective emission control. This trend has resulted in employing, for example, a fuel injected, multi-cylinder, four-cycle engine. The engine can have a direct or indirect fuel injection system and multiple cylinders such as, for example, six cylinders arranged in V-configuration. The fuel injection system enables the engine to be more responsive to operator demand, which may rapidly change. For example, the operator may desire that the engine rapidly accelerate and then rapidly decelerate within a short period of time. Fuel injection is an advantageous manner to achieve fuel economy and responsiveness under such engine operating conditions.
The fuel injection system and other sophisticated electrical devices associated with the engine require a high performance control system, which can include a control unit such as, for example, an electronic control unit (ECU), and various sensors that can sense the operator""s demands and surrounding conditions; both of which can rapidly change.
The sensors may include an intake pressure sensor that senses an intake air pressure within the intake passages. The signal sent by the intake pressure sensor, which is indicative of the intake air pressure, is highly important to determining a proper amount of fuel for injection. Typically, one intake pressure sensor is employed for a multi-cylinder engine and one of the intake passages carries the sensor. However, due to different conditions of the respective intake passages, an intake pressure sensed by the single sensor may not accurately reflect the intake pressure present in the other intake passages. Each intake passage, therefore, preferably has its own sensor. The intake pressure sensor, however, is relatively expensive. Such an approach thus has been viewed as cost prohibitive or undesirable. To address these concerns, another approach has involved a combination of an intake pressure sensor with multiple conduits connecting the sensor with the respective intake passages is proposable. U.S. Pat. No. 6,227,172 discloses an example of such an arrangement in which a single intake pressure sensor is connected to four intake passages via a conduit. The conduit bifurcates twice to reach the respective intake passages. As such, the conduit can neatly and symmetrically be divided with an even number intake passage construction. However, this is not true with an odd number intake passage construction such as three intake passages. In addition, pulsation can occur with the odd number passage construction that can affect a sensed signal because the bifurcation must be unsymmetrical.
A need therefore exists for an intake pressure sensor arrangement for an engine that can be simple in design and can inhibit the occurrence of pressure pulsation even with odd number intake passages.
In accordance with one aspect of the present invention, an internal combustion engine comprises an engine body. A plurality of moveable members are moveable relative to the engine body. The engine body and the moveable members together define a plurality of combustion chambers. A plurality of intake conduits define intake passages through which air flows. An intake pressure sensor is configured to sense intake pressure within the intake passages. An accumulator is provided and defines at least first and second outer surfaces. A plurality of first conduits is coupled with the first surface. At least one second conduit is coupled with the second surface. The first conduits connect the accumulator to the respective intake passages. The second conduit connect the accumulator to the intake pressure sensor. At least one fuel injector is arranged to spray fuel for combustion in the combustion chambers. A control device is configured to control the fuel injector based upon at least a signal of the intake pressure sensor.
In accordance with another aspect of the present invention, an internal combustion engine comprises an engine body. A plurality of moveable members are moveable relative to the engine body. The engine body and the moveable members together define a plurality of combustion chambers. A plurality of intake conduits define intake passages through which air flows. The intake conduits extend generally horizontally. An intake pressure sensor is configured to sense intake pressure within the intake passages. An accumulator is provided and defines at least bottom and vertical outer surfaces. A plurality of first conduits are coupled with one of the bottom and vertical surfaces. At least one second conduit is coupled with the remainder surface of the bottom and vertical surfaces. The first conduits connect the accumulator to the respective intake passages. The second conduit connects the accumulator to the intake pressure sensor. At least one fuel injector is arranged to spray fuel for combustion in the combustion chambers. A control device is configured to control the fuel injector based upon at least a signal of the intake pressure sensor.
In accordance with a further aspect of the present invention, an outboard motor comprises an internal combustion engine. A support member is arranged to support the engine. The engine comprises an engine body. A plurality of moveable members are moveable relative to the engine body. The engine body and the moveable members together define a plurality of combustion chambers. A plurality of intake conduits define intake passages through which air flows. An intake pressure sensor is configured to sense intake pressure within the intake passages. An accumulator is provided and defines at least first and second outer surfaces. A plurality of first conduits is coupled with the first surface. At least one second conduit is coupled with the second surface. The first conduits connect the accumulator to the respective intake passages. The second conduit connect the accumulator to the intake pressure sensor. At least one fuel injector is arranged to spray fuel for combustion in the combustion chambers. A control device is configured to control the fuel injector based upon at least a signal of the intake pressure sensor.
In accordance with an additional aspect of the present invention, an internal combustion engine comprises an engine body and a plurality of moveable members that are moveable relative to the engine body. The engine body and the moveable members together define a plurality of combustion chambers. A plurality of intake conduits define intake passages through which air flows to the combustion chambers, and an intake pressure sensor is configured to sense intake pressure within the intake passages. The intake pressure sensor is connected to the intake passages via an accumulator. A plurality of first conduits connect the accumulator to the respective intake passages. Each of the first conduits is coupled to the accumulator separately of the other first conduits. At least one second conduit is coupled with the accumulator, and the second conduit connects the accumulator to the intake pressure sensor. A least one fuel injector is arranged to spray fuel for combustion in the combustion chambers, and a control device is configured to control the fuel injector based upon at least a signal of the intake pressure sensor.
Another aspect of the invention involves an internal combustion engine comprising an engine body and a plurality of moveable members moveable relative to the engine body. The engine body and the moveable members together define a plurality of combustion chambers. A plurality of intake conduits define intake passages through which air flows to the combustion chambers. An intake pressure sensor is configured to sense intake pressure within the intake passages. A plurality of first conduits are coupled with an accumulator, and at least one second conduit is coupled with the accumulator. The first conduits connect the accumulator to the respective intake passages, and the second conduit connects the accumulator to the intake pressure sensor. At least one fuel injector is arranged to spray fuel for combustion in the combustion chambers. A fuel pressure regulator communicates with the fuel injector to regulate fuel pressure at the fuel injector, and a third conduit connects the accumulator to the fuel pressure regulator.
These and other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiment. The invention is not limited, however, to the particular embodiment disclosed.